In addition to allowing users to conduct text-based searches, image-based searches are also presently available on the Web. Accordingly, a user may conduct an image search once the user is connected to a website.
Conventional Web search engines such as Google, Yahoo and MSN have already provided image searching services. This kind of searching implements an inquiry function by building up indices based primarily on filenames of images and is therefore similar to an ordinary textual keyword search or a keyword search based on a filename. Although this filename-based searching method may satisfy typical search demands, it nevertheless fails to provide further search related to information of the image.